AbbVie has agreed to buy Gilgamesh Pharmaceuticals’ lead psychedelic candidate bretisilocin (GM-2505), targeting moderate-to-severe major depressive disorder, for up to $1.2 billion. Bretisilocin demonstrated a significant antidepressant effect in Phase IIa trials, with a favorable safety profile. This acquisition aligns with AbbVie’s strategic commitment to expanding its psychiatric portfolio and advancing novel treatments for patients with unmet needs. Gilgamesh will spin off a new company to continue development of other assets.